The FitBit's just been unveiled at the TechCrunch 50 event, and it's an interesting gizmo: it's designed to clip to your clothing where it tracks your exercise activity, a bit like Nike+. But unlike the iPod/Nike combo, it wirelessly connects to its charger/basestation which sends data to an online database that tracks your performance. And it comes with a wrist-strap so you can wear it at night. Apparently as you slip into REM sleep your wrist will tremor slightly, and the FitBit uses this to work out your sleep quality. These prototypes have no screen, but the final product will have an OLED one that includes a Tamagotchi-style avatar that'll symbolize your health status. It's due in December for $99. [Gearlog via BBG]